VPN Technology
Virtual private networks create an encrypted tunnel across untrusted networks, extending a protected network to remote users and sites.
A Private Tunnel Over a Public Network
A virtual private network (VPN) carries traffic through an encrypted tunnel across an untrusted network, most often the public internet, so that it is protected as if it traveled on a private link. VPNs let a remote worker reach internal systems securely, or connect two sites into one logical network, without exposing traffic to anyone on the path in between.
Common Types
- Remote-access VPN: an individual device tunnels into a network
- Site-to-site VPN: two networks are joined over an encrypted link
- IPsec: a protocol suite operating at the network layer
- TLS/SSL VPN: tunnels built on TLS, often through a browser or client
What a VPN Does and Does Not Do
A VPN protects data in transit and authenticates the endpoints, but it does not by itself limit what a connected user can reach. A traditional VPN that drops a remote device onto the internal network grants broad access once connected, which is why a compromised VPN account has been the start of many breaches. The tunnel is secure; the access it grants must still be scoped.
VPNs and Zero Trust
Zero-trust network access refines the VPN model: instead of placing a device on the network, it brokers access to individual applications, verifying identity and device health per request. This limits the blast radius that a broad VPN connection would otherwise create.
Fusion Context
Where authorized remote access to a fusion program's systems is needed, encrypted tunnels protect the session, but for the Hyperion breeder and burner control networks the access is deliberately scoped, brokered through the industrial DMZ, restricted to specific systems, and never a direct route to a controller, following zero-trust principles rather than granting flat network access.